BP begins static kill with mud injection

BRETT CLANTON, Copyright 2010 Houston Chronicle

Published 5:30 am, Wednesday, August 4, 2010

Photo: Pat Sullivan:, AP

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Retired Coast Guard Adm. Thad Allen gives an update on efforts to stop the oil spill in the Gulf of Mexico during a briefing at BP offices on Tuesday. He said the cleanup effort won't be done until the relief wells are completed. less

Retired Coast Guard Adm. Thad Allen gives an update on efforts to stop the oil spill in the Gulf of Mexico during a briefing at BP offices on Tuesday. He said the cleanup effort won't be done until the relief ... more

Photo: Pat Sullivan:, AP

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This image from a live BP video feed shows the Macondo's well head on Tuesday.

This image from a live BP video feed shows the Macondo's well head on Tuesday.

Photo: AFP/Getty Images

BP begins static kill with mud injection

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BP on Tuesday moved closer to bringing its Macondo well disaster to an end with the launch of a long-awaited static kill procedure, described as the first of two steps in sealing the well for good.

The procedure started in the afternoon following a test confirming it was safe to inject fluids into the well. The goal is to pump in enough heavy mud that its weight forces oil back into a reservoir nearly three miles below the seafloor.

If it works, the static kill could take pressure off the massive capping stack that has held back the flow of oil from Macondo since July 15, and could make it easier for BP to kill the well permanently with a relief well in coming days.

It also could provide new clues about the causes of the April 20 blowout that killed 11 workers and spawned the worst oil spill in U.S. history.

If leaks are discovered in the long pipe-like casing in the well's center, it could bolster suggestions that the casing may have been set improperly by contractors, allowing natural gas to escape into the wellbore, travel to the surface and ignite. Such a finding could help BP deflect some blame for the accident, which destroyed the Deepwater Horizon drilling rig.

Earlier this summer, a test of the well's integrity did not point to significant leaks, but there is a chance that leaks were undetected, said Donald Van Nieuwenhuise, director of the University of Houston's petroleum geosciences programs.

Removing doubt

"With any situation with wells, it's in the subsurface, we can't always see it," he said. "You do run into surprises all the time."

Retired Coast Guard Adm. Thad Allen, commander of the national spill response, said the new procedure should remove all doubt.

"We'll know the path of the hydrocarbons when we're done with this," he told reporters in a briefing Tuesday at BP's west Houston office.

The static kill began about 3 p.m. Tuesday after BP completed an injectivity test that entailed pumping small quantities of oil down the well at rising rates.

Originally slated for Monday night, the test was delayed after hydraulic leaks were discovered in the massive capping stack and blowout preventer sitting on top of the Macondo wellhead on the seafloor.

Once valves were locked shut, the test commenced.

Time is of the essence

While leaks do not necessarily suggest structural problems with the well, Allen emphasized: "I think we all need to understand the quicker we get this done, the quicker we reduce the risk of any type of internal failure we may not be aware of."

The static kill could take about 30 hours if casing in the well is fully intact and up to 60 hours if there are leaks, Allen said.

The latter scenario would be slower because mud would have to be pumped both inside the casing and into the area between the casing and the well bore, called the annulus. Within hours after the procedure begins, pressure readings should tell crews more about the condition of the well, he said.

A key indicator

Kent Wells, senior vice president with BP, said the clearest indication the static kill is successful will be if the weight of drilling mud alone can contain the well without the closed valve on top.

If that happens, the company will decide whether to pump cement into the well from the top or wait for a relief well to reach Macondo in coming days and pump cement from the bottom, he said.

The first of two relief wells is now fully constructed and should be ready to intercept Macondo by Thursday, Wells said.

BP has said the bottom kill should be completed by mid-August.

In theory, the static kill alone could seal Macondo permanently, making the relief well step unnecessary. But Allen made clear Tuesday he does not consider the relief well optional.

'No ambiguity'

"There should be no ambiguity about that. I'm the national incident commander, and that's the way this will end," he said. "It will end with the relief wells."

Allen's commitment suggests he's keenly aware of what's at stake both for the Gulf and his legacy as the nation's point person on the spill, Van Nieuwenhuise said.

"You don't get to be an admiral in the Coast Guard," he said, "if you've lost a ship before."